The paper discusses issues connected with the use of selected indices (WIBOR, WIBID, WIRON, POLONIA) as benchmarks for bank loans. In the introduction, the author addresses the problem of manipulation of rates, which are characterized by the forecasting of interest rate values. The following part of the paper analyses the differences in benchmarks’ construction, describes their operation, methods of setting and use. It also outlines their behavior over time. Subsequently, issues relating to the application of WIBOR, WIBID, POLONIA, WIRON as benchmarks for consumer loans are presented. They have been compared to a sample bank offer based on a fixed interest rate. The final conclusions outline the possible effects of various benchmarks on borrowers, and compare the situation of the Polish banking offer for fixed-rate loans with other countries. The possible effects of new regulations in the context of the share of fixed-rate loans in the credit market are also described.